Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 24, 2007
Publication Date: July 8, 2007
Citation: Reinhardt, T.A., Lippolis, J.D. 2007. Developmental changes in milk fat globule membrane proteome expression during the transition from colostrum to milk [abstract]. 2007 Joint Meeting-American Dairy Science Association, Poultry Science Association, Asociacion Mexicana de Produccion Animal, American Society of Animal Sciences. p. 58. Technical Abstract: Shotgun Proteomics, using amine-reactive isobaric tags (iTRAQ) was used to quantify protein changes in milk fat globule membranes (MFGM) that were isolated from day 1 colostrum and compared to MFGM from day 7 milk. Eight Holstein cows were randomly assigned to 2 groups of 4 cow sample pools for a simple replication of this proteomic analysis using iTRAQ. iTRAQ labeled peptides from the experiment sample pools were fractionated by strong cation exchange chromatography followed by further fractionation on a microcapillary high performance liquid chromatograph connected to a nanospray-tandem mass spectrometer. Data analysis identified 138 bovine proteins in the MFGM with 26 proteins up-regulated and 19 proteins down-regulated in day 7 MFGM compared to colostrum MFGM. Mucin 1 and 15 were up-regulated greater than 7 fold in MFGM from day 7 milk compared to colostrum MFGM. The tripartite complex of proteins of adipophilin, butyrophilin, and xanthine dehydrogenase was individually upregulated in day 7 MFGM 3.4, 3.2, and 2.6 fold, respectively, compared to colostrum MFGM. Additional proteins associated with various aspects of lipid transport synthesis and secretion such as acyl-CoA synthetase, Lanosterol synthase, lysophosphatidic acid acyltransferase, and fatty acid binding protein were up-regulated 2.6-5.1 fold in day 7 MFGM compared to colostrum MFGM. In contrast, apolipoproteins A1, C-III, E and A-IV were down-regulated 2.6-4.3 fold in day 7 MFGM compared to colostrum MFGM. These data demonstrate that quantitative shotgun proteomics has great potential to provide new insights into mammary development.